A current method of changing the shoe to correct a rotational foot ailment of a person, particularly a child that rotates the foot in or out, is by placing a wedge on the sole of the shoe creating a high spot. Similar to a tank with one track stopped, such wedge causes rotation of the shoe by virtue of its hitting the ground first and spinning on it at this point. Therefore, correction occurs.
My present invention is to accomplish the same turning or rotation but instead of pivoting on a high spot on the sole of the shoe, I create a friction surface on one spot or place on the sole causing the shoe to rotate, thus effecting correction, without some of the undesirable effects that an elevated wedge causes. (i.e. pronation or supination of the foot.)
The friction surface may either be applied with tape or rubber, or the like, or may be manufactured directly into the sole by the use of such friction material. If the friction surface is placed on the lateral side (5th toe side of the shoe) the shoe will turn or spin outward causing external rotation. Conversely, if the friction surface is placed on the medial surface of the sole, i.e. the great toe side of the sole, then internal rotation or inward turning or rotation occurs.
Heretofore, certain rubber discs were applied to the sole of a shoe with an adhesive, the opposite side having anti-slipping means, such as burlap, but such devices were for anti-skid purposes as described in U.S. Pat. No. 1,747,603. Non-skid patches with ridges were also applied to the sole as described in U.S. Pat. No. 3,561,140. Also, parallel ribs of rubber protruding beyond the surface of the sole were used for the same purpose, as shown in U.S. Pat. No. 3,295,230. Tapered raised portions on the sole and heel were also used to twist the foot back to normal position, as described in U.S. Pat. No. 1,958,097. Correcting the walking angle by elevating the medial side of the shoe with an elevated foresole and heel was also used as shown and described in U.S. Pat. No. 2,615,190. U.S. Pat. No. 3,532,098 provides for a plurality of resilient projections extending from the heel or sole of the shoe, the projections being disposed in pairs one on each of opposite sides of a central point on the member and such projections being formed at an acute angle with respect to the supporting side with the projections on one side of the central point being slanted in a direction opposite to the direction of those on the other side of the central point so that the projections bend in response to the weight of the shoe wearer to cause rotation about such central point in a plane substantially parallel to the member upon ground engagement of the shoe, as described in U.S. Pat. No. 3,532,098. U.S. Pat. No. 3,470,879 reveals a shoe element for heel and/or sole having a plurality of resilient, parallel, spaced ribs, arranged at an acute angle with respect to the longitudinal axis of the element and canted towards one end of that axis. When the ribs engage the ground under the weight of the wearer, the element and shoe shifts laterally to correct "toe-in" or "toe-out", depending upon the direction the ribs are slanted. Likewise, U.S. Pat. No. 3,463,165 reveals a plurality of deformable studs which extend outwardly obliquely from the sole and/or heel of the shoe for deformation upon the application of the weight of the wearer to impart a force to the member which is opposite to the direction of the oblique extension of the studs. However, these patents do not create the friction surface on a specific place on the sole to cause the desired shoe rotation in order to effect the necessary correction required.
An object of my invention is to provide a means of correction individually directed to the correction of specific problems and deformaties of many kinds and types but especially for the younger child where correction at an early age will correct the problem while the child is growing and reduce the period of correction over that heretofore required by conventional devices.
Another object is to provide means capable of effecting such improved correction by friction means while permitting in most cases full mobility of the wearer without certain disadvantages inherent in wedges.
A further object is to provide a friction means on the sole which is inexpensive, easy to apply, or to manufacture, or to remove if necessary, comfortable to use and which does not place undue strain on the wearer.
Other objects and advantages of my invention will become more apparent upon reference to the following description and the accompanying drawings.